Structure of panel for flat type cathode ray tube

Abstract

A structure of a panel for a flat type cathode ray tube having an outer panel surface approximating a completely flat surface and an inner panel surface with a radius of curvature is provided. A difference between a panel thickness at a central part of the panel and a panel thickness at each of the diagonal corner parts of the panel satisfies a condition of 1.7<=T2/T1<=2.2, where T1 represents the panel thickness at the central panel part and T2 represents the panel thickness at the diagonal corner panel parts. Further, compressive stresses exhibited at at least one part of the outer panel surface satisfy a condition of 6.0 MPa<=|sigma|<=15.0 MPa, where sigma represents the compressive stresses exhibited at at least one part of the panel. This panel structure can maximize an effect of preventing an in-furnace thermal breakage of the panel.

What is claimed is:  
     
       1. A structure of a panel for a flat type cathode ray tube having an outer panel surface approximating a substantially flat surface, and an inner panel surface with a radius of curvature, wherein: 
       a difference between a panel thickness at a central part of the panel and a panel thickness at each of the diagonal corner parts of the panel satisfies a condition of 1.7≦T 2 /T 1 ≦2.2, where T 1  represents the panel thickness at the central panel part, and T 2  represents the panel thickness at the diagonal corner panel parts; and  
       compressive stresses exhibited at at least one part of the outer panel surface, at the central part of the panel, and at a seal edge part of the panel respectively satisfy a condition of 6.0 MPa≦|σ|≦15.0 MPa, 10.0 MPa≦|σ C/C |≦15.0 MPa, and 6.0 MPa≦|σ S/E |≦9.0 MPa, where σ represents the compressive stresses exhibited at the at least one part of the outer panel surface, σ C/C ′ represents the compressive stress exhibited at the central part of the panel, and σ S/E  represents the compressive stress exhibited at the seal edge part of the panel.  
     
     
       2. The display panel according to  claim 1 , wherein among the compressive stresses, that exhibited at the central panel part is determined to satisfy a condition of “10.0 MPa≦|σ C/C |≦15.0 MPa”, where, “σ C/C ” represents the compressive stress exhibited at the central panel part. 
     
     
       3. The display panel according to  claim 1 , wherein among the compressive stresses, that exhibited at a seal edge part of the panel is determined to satisfy a condition of “6.0 MPa≦|σ S/E |≦9.0 Pa”, where, “σ S/E ” represents the compressive stress exhibited at the seal edge panel part. 
     
     
       4. A structure of a panel for a flat type cathode ray tube having an outer panel surface approximating a substantially flat surface, and an inner panel surface with a radius of curvature, wherein: 
       compressive stresses exhibited at at least one part of the outer surface, at the central part of the panel, and at a seal edge part of the panel, in a state in which the panel is assembled into a cathode ray tube, respectively satisfy a condition of 5.5 MPa≦|≦σ|12.5 MPa, 9.0 MPa≦|σ C/C |≦12.5 MPa, and 5.5 MPa≦|σ S/E |≦8.5 MPa, where a represents the compressive stresses exhibited at the at least one part of the panel, σ C/C  represents the compressive stress exhibited at the central panel part, and σ S/E  represents the compressive stress exhibited at the seal edge panel part.  
     
     
       5. The display panel according to  claim 4 , wherein among the compressive stresses, that exhibited at a central part of the panel is determined to satisfy a condition of “9.0 MPa≦|σ C/C |≦12.5 MPa”, where, “σ C/C ” represents the compressive stress exhibited at the central panel part. 
     
     
       6. The display panel according to  claim 4 , wherein among the compressive stresses, that exhibited at a seal edge part of the panel is determined to satisfy a condition of “5.5 MPa≦|σ S/E |≦8.5 MPa”, where, “σ S/E ” represents the compressive stress exhibited at the seal edge panel part. 
     
     
       7. A flat type cathode ray tube comprising the structure of  claim 1 . 
     
     
       8. A flat type cathode ray tube comprising the structure of  claim 4 . 
     
     
       9. An improved display panel for a flat type cathode ray tube having an outer panel surface approximating a substantially flat surface, and an inner panel surface with a radius of curvature, the improvement comprising: 
       a difference between a panel thickness at a central part of the panel and a panel thickness at each of diagonal corner parts of the panel satisfies the following equation:  
       
         
           1.7≦ T   2 / T   1 ≦2.2  
         
       
        where T 1  represents the panel thickness at the central panel part, and T 2  represents the panel thickness at each of the diagonal corner parts; and  
       compressive stresses exhibited at at least one part of the outer panel surface, at the central part of the panel, and at a seal edge part of the panel respectively satisfy the following equations:  
       
         
           6.0 MPa≦|σ|≦15.0 MPa  
         
       
       
         
           10.0 MPa≦|σ C/C |≦15.0 MPa  
         
       
       
         
           6.0 MPa≦|σ S/E |≦9.0 MPa  
         
       
       where σ represents the compressive stresses exhibited at the at least one part of the outer panel surface, σ C/C  represents the compressive stress exhibited at the central part of the panel, and σ S/E  represents the compressive stress exhibited at the seal edge part of the panel.  
     
     
       10. A flat type cathode ray tube comprising the structure of  claim 9 . 
     
     
       11. The improved display panel for a flat type cathode ray tube having an outer panel surface approximating a substantially flat surface, and an inner panel surface with a radius of curvature, the improvement comprising: 
       compressive stresses exhibited at at least one part of the outer surface, at the central part of the panel, and at a seal edge part of the panel, when the panel is assembled into a cathode ray tube, satisfy the following equations:  
       
         
           5.5 MPa≦|σ|≦12.5 MPa  
         
       
       
         
           9.0 MPa≦|σ C/C |≦12.5 MPa  
         
       
       
         
           5.5 MPa≦|σ S/E |≦8.5 MPa  
         
       
       where σ represents the compressive stresses exhibited at the at least one part of the panel, σ C/C  represents the compressive stress exhibited at the central part of the panel, and a σ S/E  represents the compressive stress exhibited at the seal edge part of the panel.  
     
     
       12. A flat type cathode ray tube comprising the structure of  claim 11 . 
     
     
       13. An improved display panel for a cathode ray tube having a panel with a substantially flat outer surface and an inner surface having a radius of curvature, the improvement comprising: 
       a difference between a panel thickness at a central portion of the panel and a panel thickness at each of diagonal corner portions of the panel satisfies the following equation:  
       
         
           1.7≦ T   2 / T   1 ≦2.2  
         
       
       where T 1  represents the panel thickness at the central portion of the panel, and T 2  represents the panel thickness at each of the diagonal corner portions of the panel.  
     
     
       14. The improved display panel according to  claim 13 , wherein compressive stresses exhibited at the outer surface of the panel satisfy the following equation: 
       
         
           6.0 MPa≦|σ|≦15.0 MPa  
         
       
       where σ represents the compressive stress exhibited at the outer surface of the panel. 
     
     
       15. The improved display panel according to  claim 13 , wherein the compressive stress exhibited at the central portion of the panel satisfies the following equation: 
       
         
           10.0 MPa≦|σ C/C |≦15.0 MPa  
         
       
       where σ C/C  represents the compressive stress exhibited at the central portion of the panel. 
     
     
       16. The display panel according to  claim 13 , wherein the compressive stress exhibited at a seal edge portion of the panel satisfies the following equation: 
       
         
           6.0 MPa≦|σ S/E |≦9.0 MPa  
         
       
       where σ S/E  represents the compressive stress exhibited at the seal edge portion of the panel. 
     
     
       17. The improved display panel according to  claim 14 , wherein compressive stresses exhibited at the outer surface of the panel, in a state in which the panel is assembled into a cathode ray tube, satisfy the following equation: 
       
         
           5.5 MPa≦|σ|≦12.5 MPa  
         
       
       where σ represents the compressive stresses exhibited at the outer surface of the panel. 
     
     
       18. The improved display panel according to  claim 17 , wherein the compressive stress exhibited at a central portion of the panel satisfies the following equation: 
       
         
           9.0 MPa≦|σ C/C |≦12.5 MPa  
         
       
       where σ C/C  represents the compressive stress exhibited at the central portion of the panel. 
     
     
       19. The improved panel according to  claim 17 , wherein the compressive stress at a seal edge portion of the panel satisfies the following equation: 
       
         
           5.5 MPa≦|σ S/E |≦8.5 MPa  
         
       
       where σ S/E  represents the compressive stress exhibited at the seal edge portion of the panel. 
     
     
       20. A flat type cathode ray tube comprising the structure of  claim 13 .